When riding the subway, it’s not uncommon to see signs warning travelers of route changes and to be wary of pickpockets; however, According to the UK’s Daily Mail, London’s Farringdon Station has an uncommon warning for tube users:

“The mice at this station have been attacking customers. Please place the bottom of your trousers into your socks to avoid being a victim of the Farringdon mice.”

Apparently, mice have been “attacking” the feet of commuters as they wait for their train. It’s a bit of a mystery, however, as tube staff deny being the ones to put the sign up. While it’s now been taken down, thousands of people have already seen it and have taken to Twitter to spread the word.

For example, @alfredcamp wrote, “The #EssexLion turned out to be a harmless pussycat. The #FarringdonMice turned out to be far more sinister!”

@AlexKammAndSons also tweeted, saying, “I am not passing through Farringdon without a packet of mini cheddars as mouse bait #Farringdonmice.”

And @secret_escapes is now having nightmares. “Last night I dreamt that I was savaged by a (very large & scary) mouse. Now this warning appears. OMEN. #FarringdonMice”